Mon, Feb 26, 2018 11:46 pm

When I attempted to send a
PKI-encrypted email message to several recipients
from Microsoft Outlook for Mac 2016 (version 15.41),
I saw the message "Encryption certificates for some recipients could
not be found in the Outlook Contacts. Do you want to search the
Active Directory servers for them?"

I clicked on OK and then saw the message "The following recipients
have encryption certificates with security problems. Do you still want to
send this encrypted message?"

I clicked on Cancel and checked on whether Outlook was storing a
public key certificate for the person in my contacts list. He
was in the contact list, but there was no certificate associated
with the person in the contacts list when I clicked on the
Certificates tab.